Prolonged estuarine habitat use by dusky grouper Epinephelus marginatus at subtropical latitudes revealed by otolith microchemistry

Abstract

Otolith microchemistry (Sr:Ca, Ba:Ca) was used to evaluate habitat use patterns of the endangered dusky grouper Epinephelus marginatus in southern Brazil. Individual Sr:Ca profiles exhibited low variation, with an overall tendency to increase with age. Interestingly, individual Ba:Ca profiles presented 3 contrasting patterns: the first comprised most sampled individuals (> 80%), mostly indicative of the predominant use of marine waters throughout their life history; the second pattern (~10% of all individuals) indicated that dusky grouper may use or remain in or near estuarine waters for short time periods; finally, the third identified pattern (~5%) comprised individuals remaining in estuarine waters for long periods and provided the first evidence for this species of prolonged estuarine habitat use (over a year), in particular during juvenile life stages.

Evaluating estuarine nursery use and life history patterns of Pomatomus saltatrix in eastern Australia

“…The lack of difference in Ba concentrations between the coastal-and estuarine-caught fish in the present study is possibly because the estuarine re gions where P. saltatrix were collected were higher in salinity (> 25) than regions where salinity is low enough to produce the high Ba:Ca signal commonly observed in other studies (Macdonald & Crook 2010). Overall, analysis of otolith Sr:Ca and Ba:Ca profiles can be used to trace estuarine−ocean movement in P. saltatrix, and concur with both the spot analyses and re-analysis of historical coastal length frequencies to indicate that the life history of P. saltatrix in eastern Australia is more facultative than previously thought, a finding shared with several studies that have investigated life history patterns in fish (Milton et al 2008, Gillanders et al 2015, Condini et al 2016.…”

“…Since water masses are known to vary in their environmental conditions over time and space, fish collected in different environments are expected to have different otolith elemental composition (Campana et al 2000). These elemental 'signatures' or 'fingerprints' have been used to successfully identify natal origins and nursery estuaries of adult fish (Gillanders & Kingsford 1996, Gillanders 2002a, Vasconcelos et al 2011, discriminate between populations (Rooker et al 2001, Tanner et al 2016) and determine mixed stock composition (Munch & Clarke 2008, Geffen et al 2011.…”

Silversides ( Odontesthes bonariensis ) reside within freshwater and estuarine habitats, not marine environments

“…Otolith microchemistry has been widely used to study the migration of teleost fish (Avigliano, et al, 2018;Avigliano, and Volpedo, 2016;Panfili et al, 2012;Tzeng et al, 2002). Several diadromous species have been studied in Latin America (Avigliano, and Volpedo, 2016;Condini et al, 2016;Daros et al, 2016), and the relationship between water Sr:Ca ratios and salinity in large estuaries has been reported (Albuquerque et al, 2012;Avigliano, and Volpedo, 2013a). In this study, otolith Sr:Ca variations have been useful for documenting cyclic migratory patterns between freshwater and estuarine water for O. bonariensis silverside.…”

Coastal streams constitute alternative habitats for juveniles of an overexploited mullet species

“…Repeatability was estimated as the relative standard deviation (RSD) from 10 consecutive measurements of the standard NIST 1834, resulting in relative standard deviations of 6.91 and 3.99% for 86 Sr and 43 Ca, respectively. All additional procedures for otolith chemical analysis followed Condini et al (2016).…”